Artificial structure and process of producing same



,PatentedDec. 9,1941 n I r I UNITED- STATES PATEN OFFICE 2,265,915 V ARTIFICIAL STRUCTURE AND PROCESS OF PRODUCING SAME Leon Lilieni'eld, deceased, late of Vienna, Ger many, by Emerich Hunna,executor, Vienna,

Germany; Antonie Lilienield, administratrix of said Leon Lilieni'eld, deceased, assig'nor to Lilienield Patents Inc., Boston, Mass.,'a corporation of Massachusetts No Drawing. Application August 20, 1940, Serial No. 353,420. In Great Britain March 15, 1930 o V 27. Claims. (Chili- 5th In the prior applications of this inventor,

per liter 160 grams dfmsor'snd 320 grams of 435,647 and 435,648 (How U. S. Patents 1,858,097

} NaHS'Qe, or a bath containing 25-30% of amand 2,021,861 respectively), is described a process monium sulphate and optionally -20% 01 of making artificial structures including arti- H2804, or a bath consisting of 500 parts 01 Nail ficial threads, films, coatings, dressings, etc.-, in 5 804 and76 parts of HilSQi'Of 66 36. and 587 which hydroxy-alkyl derivatives (probably hy-; parts of water,-or a bath consisting of 180 parts droxy-alkyl ethers) of cellulose are made by re- 0t Na2SO4, 60, parts of ammonium sulphate and acting with a halogen derivative of a polyhydric parts of zinc sulphate, 135 parts of glucose, alcohol; (e. g. a chlorhydrin of a glycol or of 128 parts of H2504 and 982 parts of water, or glycerine) upon alkali cellulose.- This product- 10 nitric acid of 00-90% strength, orphosphoric (as the crude reaction product or after purificaacid of 67.5% to 99% strength, or arsenic acid of tion or isolation) isthen xanthated by action 60+90%. strength, or a 60% solution of zinc thereupon of CS: and an alkali, e. g.NaOH. The chlorid, with or without.5-6% of HCl, added. resulting product (believed to be a xanthate of These would be considered as plasticizing a polyhydricalcohol ether of cellulose), is then baths." Or the shaped soluticnoithe xanthate dissolved in an alkaline solution, to form a more can be first introduced into one ;oi' the usual or less viscous solution, which can be then co- .non-plasticizing baths commonly used in the visagulated and plasticized by;shaping and treatcose industry (e. g. 10-15% H2804 etc.'), and ment with a. coagulating bath, which may also then the freshly coagulated structure can be be a coagulating and plasticizing bath, e. g. s treated with one of the above plasticizing baths strong acid, such as H2804 of 35% strength. It is or any other plasticizing bath known in the art. "5 preferable to also apply stretching during this With the use of plasticizing baths, artificialtreatment. The artificial structures produced structures (e. g, artificial threads) of very high f; are characterizedby possessing a high tenacity (both in the dry and wet state), a high extensipared with ordinary viscose silk.

The present invention'is an improvement in or a modification of'that described in said application,435,648, filed March 23, 1930 (now'U. S. .Patent No. 2,021,861).

The coagulating baths used for the production of the artificial structures herein (as in Patent 2,021,861) may be any of the coagulating baths commonly used in the coagulation of artificial structures from viscose, e. g. 53-15% solution of sulphuric acid, with or without the addition of neutral salts; or acid salts such as sodium bisulph-ate-of like acidity, or solutions of ammonium salts of strong acids, e. g. ammonium sulphate or chloride, etc. Such solutions will hereinafter be referred to as simple coagulating baths.

But also advantageously the so-called plasti cizing baths heretofore proposed for the production of strong threads from viscose, can also be employed. Such plasticizing baths may contain 35% or more of sulphuric acid or other solutions of equivalent acidity, containing other acids or acid salts or mixtures including ammonium salts. Or alternatively the xanthate solutions can be introduced first into any simple coagudry-and wet tenacity are formed.

Coagulatingbaths as used 'in said am 2,021,861 (whetherplasticizlng or not) are also suitable in the present case.-

-In continuing his researches based on said apthreads having similar properties if, instead of the xanthates oi hydroxy-alkyl derivatives of cellulose, xanthatesoI-other cellulose ethers, and particularly xanthates of'alkali soluble alkyl or aralkyl ethers of cellulose or xanthates of alkali soluble. cellulose ethers of hydroxy acids (e. g.

.hydroxy-fatty acids) are 'usedfor the manulating bath-commonly used inthe viscose industry, and then'the freshly coagulated structures 5 treated with one of the so-called plasticizing; baths, referred to above. a

The shaped solution of the xanthate-of celluflose ether is preferably introduced into a coagufacture oi-.a.rtificial structures, for example artificial threads.

The process consists in giving a solution containing one or more of the xantbatesof the cel-' lulose ethers set forth above, the shape ofan artificial structure desired, for example thread, and contacting the thus shaped solution with one or more suitable coagulating agents, or setting baths, such as those mentioned above. 1

As to the nature and properties of the alkyl or aralkyl ethers of cellulose to be xanthated for the present process, according to the knowledge obtained in the workof this inventor, it appears that so long as they are insoluble or substantially insoluble in water, most alkyl or aralkyl ethers of cellulose are very suitable for the present process, provided that they 'are soluble in canstic alkali solution or provided that they contain insufiicient of the alkyl-oraralkylfradical tobe soluble in the usual volatileorganic solvents;

"I'hcse alkyl or aralkyl derivatives of cellulose agent.

which are insoluble'in caustic aumii solution, but

- which are capable of absorbingcaustic alkali solution are also to some degree suitable for being a content of the substituent radical, connected ether fashion to the cellulose radical.

xanthated. In other words, the, alkyl or aralkyl ethers should be capable of absorbing caustic alkali solution.

Practically the same holds good with the c u lose ethers of hydroxy acids to be xanthated for the present process. According to the inventors knowledge, those that are soluble in caustic alkali solution are preferred, but at any event they must be capable of absorbing caustic alkali solution, in order to be used in this process, to

give good products.

As stated above, the present process consists in bringing a solution of axanthate of an alkalisoluble alkyl or aralkyl derivative of cellulose, or a-xanthate of an alkali-soluble cellulose ether of ahydroxy acid into the form of an artificial structure, and contacting it with a coagulating This latter may also, if desired, have also a plasticizing effect on the artificial structure during, or immediately after, its coagulation. It is also possible to first act upon the shaped solution with a coagulating agent and also, if

desired, thereafter with an agent which has a plasticizing effect on the freshly coagulated material. I

The plasticizing effect referred to can be accomplished in either of two 'ways (a. g. in the manufacture of :supportless artificial structures, e. g. artificial threads).

ample any of the coagulating baths commonly used in the viscose silk industry, for example a dilute solution containing a small percentage of an acid material, such as an acid salt or 5 to 'of sulphuric acid, alone or alsocon'taining' dis- (i) The solution canbe introduced into a coagulating bath, for ex- ,cellulose or of a xanth'ate of a cellulose ether of a hydroxy acid with viscose or by dissolving cellulose xanthate (sulphidized alkali cellulose) in a solution of a xanthate of an alkylor aralkylcellulose or of a xanthate of a cellulose ether of a hydroxy acid by dissolving a xanthate of an alkylor aralkyl-cellulose or a xanthate 'of a cellulose ether of a hydroxy acid in viscose, 1 or by conducting the present process so that the 6/ carbon bisulphide is allowed to act in the presence .of caustic alkali upon a mixture of an 'alkyl or aralkylderivative of cellulose and cellulose, or upon a mixture of a cellulose ether of a hydroxy acid and cellulose, for example by treating alkali cellulose with an alkylating or aralkylating agent solved salts (e. g. MgSO4, Na2SO4, alum etc.) or

sugars (e. g. glucose, etc.) or softening agents, (e. g. glycerine) etc., andthe freshly coagulated thread can then pass into a plasticizing bath such as a solution of H2804 of 35% or stronger, or other acid or acid material of equivalent strength, or a mixture of such acids, or any of the plasticizing baths set forth above. (2) Or the thread-like stream of-the solution can pass directly into such plasticizing bath. The plasticizing bath may also contain salts, acid salts,

sugars, softening agents, etc. A bath of sulphuric acid containing according to the spinning properties of the solution, to 7(l%' of H280; is very useful for thispurpose. Theaction of the strong acid bath is stopped whenits efiect has been sufficiently accomplished, e. g. washing, 'refrigerating, or the like.

The'xanthates of the alkali-soluble alkyl or aralkyl ethers of cellulose or of the alkali-soluble cellulose ethers of hydroxy acids (namely ethers of hydroxy fatty acids or of other hydroxycarboxylic acids e. g. of hydroxy-succinic acid) may be prepared for example according to the processes described in the copending application 521,023 of this inventor, or according to any other suitable process or method. Satisfactory to xanthation. The ethers contain only a low or with a halogen fatty acid under such conditions that only part of the cellulose contained in the alkali cellulose is converted into the corresponding ether of cellulose and thereafter, by

acting upon this intermediate product with carbon bisulphide, converting the thus obtained reaction mass into a mixture of a xanthate of .the corresponding ether with cellulose xanthate. Also other alkali soluble derivatives of cellulose or alkali'soluble cellulose hydrates or proteins or gelatine may be added to and mixed with the xanthates of the cellulose ethers.

Any suitable softening agents, such as glycerine I or a glycol or a sugar, such as glucose or a, soap or Turkey-red oil, or a drying or non-drying oil, or any elasticizing agents, for example a halogen derivative of a dior a polyvalent'alcohol, particularly a halohydrin, such as a dichlorohydrin or a mono-chlorohydrin or ethylene chlorohydrin may be added to the solutions of the xanthates.

Within the broad scope ofrthe invention, any

chemical. coagulating or precipitating agent or mixture of precipitating agents or mixture of precipitating agents with other inorganic or organic substances known in the viscose art may be used in the present process. Excellent results, particularly with regard to tensile strength, are obtained when thefreshly 7 coagulated I material is exposed to the action of a plasticizing agent (but-this step is optional). This purpose can be accomplished either by using as thesetting bath a liquid which has a coagulating effect on the shaped'solutions of xanthates of alkyl or aralkyl ethers of cellulose, or the xanthates'of hydroxy-carboxylic acid ethersof cellulose and a plasticizing effect on the coagulated solution (for example,a bath containing not less than 35 per cent of sulphuric acid monohydrate or an equivalent quantity of another. mineral acid or=a fairamount of a zinc halide,'-e. g. 48 to of zinc-chloride, alone or mixed with an acid), or by employing as setting bath a liquid that has only a coagulating effect on the formed solutionsof said xanthates (for example, any coagulating butihot plasticizing bath known in the viscose art) and subsequently (if desired), acting upon the freshly coagulated artificial structure with a bath thathas a plasticizing effect on it, for example with a liquldhaving a highcontent of strong mineral acid, particularly having a sulphuric acid content ofnot less than of monohydrate, or the plasticizing baths given above.

Since the practice of the process is parallel to that set forth in the aforesaid specification, Ser. No. 435,648 and explained therein by aid of humerousexamples, it appearsv unnecessaryto repeat here all particulars relating to the carrying out of the present process under. various working conditions and to give here examples demon grams of NazSO4 which about C; In this bath the sodium sulphate is given as an example of a soluble sulphate. V

Also a bath of 10% sulphuric-acid at 16 C. or

40 0., can be used in this and the following examples.

Furthermore, in this and the; following exam- 7 pies, a coagulating and plasticizin'g bath containing over 35 percent of H2804, and

at least '45;per"cent of HzSOQ-eig." percent 7 or per center per cent or' percent or vstrating all possible modifications of executing the present invention. In conjunction with the detailed description and the examples of specification Ser. appear to be execution of no way limited to these examples.

Example I sufilcient to illustrate the practical No. 435,648, the following examples 7 the invention which however is by 1000 parts of wood-pulp (moisture 9 to 10 per cent) or 1000 parts of cotton linters (moisture 7 to 8 percent) are steeped in 20,000 parts of caustic soda solution of 18 per cent strength at "15 C., and the reaction mixture is allowed to stand for 3 hours at room temperature. After this time the alkali cellulose is pressed down to 3400 parts and comminuted in a shredder at 12 to 13 0., whereupon parts of dimethyl sulphate are added in a few portions, and the reaction mass kneaded in a shredder'for about 3 hours. Thereafter the reaction mass is transferred to a vessel, provided with a lid and kept in the closed vessel for 21 hours at 20 C.

The reaction mass is now placed in a filter press or on a straining cloth and washed with water until free from alkali, whereupon it ispressed down to about three to fourflf'times the weight of the parent cellulose. 'Ihewater content of the pressed product can be determined by drying a sample at C. V

The mass is now (at 15 C.) well mixed with such amounts of water and caustic soda as to give a mass containing 20,000 parts of a caustic;

soda solution of 18 per cent strength. In selecting the amounts of caustic soda and water to be used, the water content of the pressed mass is taken into consideration. L

The reaction mixture is nowallowed to remain at room temperature for 3 hours, whereupon it is pressed down to 3400 to 4500 parts and comminuted in a shredder for 3 hours at 12 to 13 C. Immediately after shreddnig 600 parts of carbon bisulphide are added, and the reaction mass.

and filtered, is spun in a. manner similar to the methods described ,in the examples of U. S. Patent 2,02l,861. Thus, in this and the following examples of "the present application thesolution R of the xanthate (after filtration-several times if i necessary) can be forced in well known manner through a spinning nozzle into a coagulating bath, for example the coagulating bath containing ineach liter v grams of H2504 and 320 and about 8 per cent of for 3 hours extruded 70 per cent may be used.

Or thestream of xanthate solution can be first 0 into a singlecoagulating bath,such"=as the well known Muller bath, and then it'canpass through a plasticizing bath, as mentioned above. Instead of sulphuric-acid, the -plasticizing bath can be 1 another mineral acid of equivalent strength, or a strongzinc halide (e. g. ZnClz solution of 60% strength) with or without the addition of an acid (e. g. a,60% or without 4 to 6% of H01) The details of the spinningioperation'are well known in the art.

It isfavorable to subject the threads to stretching during the process of making same. This step is-tosome extentoptional. 0

Also when plasticizi'ng coagulating baths are usedin this or the following'-'examples, during spinning} stretching, i. e. stretching additional to the degree of tensionnecessary to conduct the thread from the spinning nozzle to the collecting device. But the use of a necessary condition.

7 7 p Example I! i The process is'conducted. as in Example I, but with the diiiference that the alkyl cellulose 'xanthate isdlssolved in such a manner that the spinning solution contains about 4 to 6.5 per cent ;-.of precipitable cellulose body and 5 per cent of NaOH. 7 r Example III:

1000 parts of wood pulp or cotton linters are steeped in 20,000 parts of caustic soda solution of 18 per cent strengthat 15 (3., and the reac- 'tion mixture is allowed to stand for 3 hours at cent strength) and that the room temperature. After this time the alkali cellulose is pressed down to 3400 parts and comminuted'in a shredder for 3 hours at 12 to 13 C., whereupon 200 partsjof .dimethyl' sulphate are added in a few portions, and the reaction mass kneaded in a shredder for 3 hours at 20..C.

Thereafter the reaction mass is transferred to a vessel, provided with alid, ndkept-in the closed vessel for 21 hours at 20 C.v a

A sample taken at thattime shows that the mass in greaterpart has become soluble in dilute caustic soda solution (for filtered solution. on being acidified withdilute sulphuric acid, yields a bulky precipitate.

Y The mass is now dissolvedin 75,000, ;parts of' a caustic soda solution-o1" 8'per cent strength, 1 wherein it .dissolvesnot completely, but leaving an undissolved residue} After standing for 12 hours at room temperature, the solution is-fllfrom the mother liquor in a filter press or on a tered and the; clear filtrate precipitated by acidifying with 'sulphuricacid of .15 per cent strength. The flocculent precipitate is freed straining cloth; washedfwith water until free I from acid, pressedand its water content is determined. This material is now: dissolved in bath canlbe used at preferably ZnClg solution with the thread "may be given additional additional stretching is not' instance 01'10 per :48 hours, and has :sulphate could be .lulose v xanthate produced from :ployed inthc present process.

mass heated described in said U. S. Patent product 'or molecule or cellulose (cannon,

thirds of a such aquantity of water and caustic soda as to yield a solution containing about 5-7 per cent of methyl cellulose and .8 per cent of NaOH.

To this solution 100 per cent of carbon bisul phide (calculated on the weight of the cellulose methyl ether) are added and the reactionmixture kept with shaking or agitation for 20 hours at zo c. I

After the solution has attained a. total age been filtered during aging, the solution is spun in a manner similar to. the methods described in the examples of my speciflcation Ser. No. ;435,648. u

In this example 200 parts of dimethyl 'sulphate were used. Other amounts of this material, such as 100 to 600 parts of the dimethyl used.

' Example IV A crude ethyl cellulose xanthate is prepared as in Example I, but with the, difference that, instead of dimethyl sulphate 100 to "200 parts of di-ethyl sulphate are employed. The ethyl cellulose xanthate is dissolved in such a, quantity of water and caustic soda as to yield a solution containing about 5 to 6.5 per cent ofcellulosic substance precipitable by acid and about 8 per cent of NaOH-and, after having aged for about 96 hours and been filtered, spun in a themethods described in Ex- Example V I Instead of the alkyl cellulosexanthates employed in the foregoing examples,.an alkyl celan alkyl cellulose prepared according to any one of the processes described in U. S. Patent 1,589,606 or British Patents Nos. 203,346 or 203,347, may be em- In the first of these '13 tish- Patents, No. 203,3;6, the alkyl derivatives of cellulose which are soluble in alkali solutions but not in water, as describedln U. S. Patent 1,589,606, are prepared by heating .100 parts of cellulose or an alkali-insoluble conversion product of cellulose with an alkylating agent,-e. g. 80 parts'of ethyl chloride in the presence of a quantity of solid caustic soda which is about half the .weight of the air-dried cellulose. .The cellulose is mixed with the solid caustic alkali, preferably in powder form, or with a mixture of solid caustic alkali" and saturated alkali lye, in a shredder, edge runner, or kneading -machine, and the to 100-1ll0 0..

ing agent, in an autoclave, while being agitated.

with the alkylat- NaOH, and the alkylating'ag'entis 50-100 parts caustic soda solution subsequently precipitating. lifter gently heating with the alkylating agent, the alkyl cellulose derivative is precipitated from the viscous solution by the addition of acid or water. rials are 2000 parts of viscose containing 160 170 piartslof cellulose and the same amount of mineral acid, and

of diethyl sulphate. The 'alkylating reaction in this example directly produces an alkaline soluethyl ether of cellulose.

Example v1.

Hon a 1000 parts of wood-pulp (moisture 9 to 10 er cent) or 1000, partsgof'cotton linters (moisture steeped in 20,000 par-ts'of of 18 to 21 per cent strength at C. and the mass thus obtained is allowed to stand for 3' hours at room temperature. is pressed down to 3400 parts and comminuted in a shredder for 3'hours at 12 to 13 C., whereupon 2900 parts of di-ethyl sulphate are added in a few portions, and the. reaction mass kneaded in a shredder for about 3 hours. Thereafter I the reaction mass is transferred to a vessel provided with a lid and for 21 hours at 20 C. j The reaction mass kept in the closed vessel is now" placed in a filter press or on' a straining '(!10th and, if desired, washed with water until free from alkali, whereupon it is pressed down to'about three to four timesthe weight of the parent cellulose. The

water content of the pressed product can be determined bydryinga sample at 105 C.

The mass is'now (at 15 C.) well mixed with suchQarriounts Jot water. and caustic soda, as,

" together. with the water present in the mass,

will give20,000"parts of a caustic soda solution of 18 per cent strength;

The reaction x'n'ixture is now allowed to remain at room temperature for 3 hours, whereupon it is pressed down to 3400 to 4500 parts and comminuted m" a shredder for ,3, hours at 12 to 13 C.

If the kneading' of the cellulose and caustic alkali is carried out with access of air, the mass will take up moisture therefrom.

In the second of saidBritish patents, Number 203.347, the alkyl derivatives ofcellulose which alkali solutions but not in water,

1,589,608, are prepared by treating an alkali-soluble conversion are soluble in kylating agent in a exceed one molecule a cellulose hydrate'obtained by dissolving cellulose in ammoniacal cuprlc oxide or in a strong 75 I manner similar percent of caustic soda.

' at 15 C. during which time Immediately after shredding, 600 parts of carbon bisulphide are added, and the reaction mass placed in'a closed vessel and kept therein for 10 hours at 19 C. The excess carbon bisulphide is blown oflduring 15 minutes, and the xanthated mass dissolved in water and caustic soda, for exampleso as to yield a solution containing about 5 to .7 per cent of the dry residue of the mass pressed after the alkylation and washing and 8 obtained is aged for 90 hours it is filtered twice to The solution thus threetimes throughmedicated cottonwool. The

spinning of the aged solution is performed in a to the methods described in the specification Ser. No. 435,648.

Example VII The process is conducted as in Example VI, but

examples of the I with the diiferencethat, instead of 2900 parts,

derivative of cellulose wlth an al- 7 Examples VI or VII 2200 parts'of diethylsulphate are employed.

- Example VIII v The process is conducted as in Example VII, but with the difference that, instead of 2900 parts, 290 parts of diethyl sulphate are employed.

I Example IX r The processais conducted as in either of the or VIII, but with the difference that after the ethylating step the original In an example, the reacting mate-' which already contains an.exces 's'o1 free alkali), is

reaction mass, without being "washed; (and i kept at 20 C. for 20 hours, with agitatiomto form solution containing about 6 to 7; per cent oiprecipitable cellulosic substance, and 8 pericentofr NaOH.

The filtered solution, after eethear s described hours, at C., is spun in a manner the examples of Patent 2,021,861.

Example ,X y

The process is conducted as in .v any; or the. f Examples I to Ivor VII to IX but with the ex-' ception that the alkali cellulose is allowed toma-x ture for 48 hours at 15 or C.

s can conveniently be. efiected in a bath containing or more of sulphuric acid,.or.other acid solution of like aciditisito' giveartificial structures of high dry 'andgwet tenacitm'i'The action of the strong acidbath 'on thethread'or .other'structure a solution of the xanthate of glycollic acidetherot cellulose. This solution can be kept for another 28 hours, if desired. This solution (after having been filtered) is then used to make structures according to any of the coagulation methods of this application or of the Patent 2,021,861.

In-modifications of this example there may be useeg jdnstead' embers) 200 parts" or 400 to 50o jororn oiitssodiumsaltL.

parts,- of, the monochloraceticacid' (in the Example XIII jffi'oocparts a wood-pulp or cotton has are steeped in 20,000 parts of caustic soda solution of can be checked-by subjecting the shaped structure to washing 'orfrei'ri'geifation, when the action 1 of the acid hasbeen sumcien'tly accomplished.

This can be accomplished'by subjecting the thread to a low temperature, for instance 5 to 15 C. before it is washed, which .for :instance may be done by collecting iton a hollow spool containing a cooling agent, for-instance solid carbonic acid, or a freezing mixture, orice.

After the threads (made in this or the other examples of this case) have been'washed, they may be heated or steamed at high temperatures (for instance 100 to 110 C.) before or after the drying process. 0

2,004,875, ifor instance, by treating them in the heat with a solution of NazSBHzO of 10 per cent 1 8 20% strengthat 15 C. and the reacting mixture In the manufacture oi the shaped structures from the solution of xanthate oi an alkali soluble alkyl etheroi cellulose, thecoagulation allowed to'stand for 3 hours at 15 C. whereupon the alkali cellulose is pressed down to 2,000 parts water bath in which the drum rotates, and which ,--.temperature is maintained for Shours. vAfter that time the crude reaction mass is extracted several times with alcohol of 95 per cent strength and then washed with-water and pressed down to 2200 parts. I The pressed cake is comminuted' strength for 5 minutes to one hour or with a'so1u-' cent strength for Erample. Xi

The crude xanthate of a cellulose ether of glycollic acid may be obtained if instead of the di methyl sulphate in Example I, hereof, 300 parts of monochloroacetic acid is employed. Such xanthate is dissolved in such quantities of water and caustic soda as to yield a solution containing about'5 to 6.5 per cent of cellulosic substance pre-Q cipitable by Mid and about 8 per centof NaOH.

The xanthate-i'solution, after having aged for 0 about 96 hoursand having been filtered, is spun' in a manner similar wine methods described in the examples of Patent 2,021,861.

Example XII water and caustic soda as to and wellmixed with 4600 parts of caustic soda solution of 22 per cent strength at 18 C.

-'The reaction mass is now allowed tostand for 24 hours at 18 C. and then pressed down' to 2000 parts. The pressed cake is comminuted-in a shredder for 3 hours at 11 C.,and then kept in a closed vesselfor 72 hours at 21 C., whereupon 600 parts of carbonjbisulphide are added and V allowed to react for. 10 hours at20 C. After the excess of the carbon'bisulphidehas been blown off the reaction mass is dissolved in so much water and caustic soda as toyield a solution con-" taining about 6 to 7 percent, of precipitable cellulosic substanceand 8 per cent of NaOH and the solution is filtered.

The filtered solution, after having aged for 48 hours at 15 C. is then spun in a manner described in the examples of Patent No. 2,021,861.

Example XIV The process is conducted as in the last Example IHII, but with the diflerencethat, after the benzylating step, the reaction massis; without being washed, acted upon with 600 parts of car-- bon bisulphide for 10 hours at 20 C. There sultant mass is dissolvedin such a quantity of yield a solution containing. about.6 to 7 per cent of pre'cipitable' cellulosic substance and 8 per cent of NaOH.

The filtered solution, after having aged for. 48 hours at 15 C; can be s'pun'in 'a' manner de- V scribed in the examples of U. S. Patent 2,021,861; Y

It will be understood that instead of a. single etherifying agent, as given in the above examples, a mixture of two or more etherifying agents can be usedina similar manner, or two or more etherifying agents can be added one after another, to the alkali cellulose.

Example XV The process isconducted as in any one'of the preceding examples, but with the difference that the cellulose ether xanthate is dissolved in so much water and caustic alkali as to yield a solution containing about 3 per cent of precipitable cellulosicsubstance and 5 per cent of NaOH. For the carrying out of this. example it is recommended to start with a cellulose of high viscosity (determined by the customary methods).

Example XVI 'Mode of procedure as in any one of the preceding examples, but with the difference: that to the spinning solution to 30 partsof wdichlorohydrin or a-monochlorhydrin or ethylene chlorohydrin to 100 parts of the cellulosic substance contained therein, are added after the dissolving step.

Example XVII A cotton textile is impregnated or filled, or coated, one or several times, in a suitable machine, for instance a'padding machine or a back filling machine,'or a spreading machine, with a spinningsolution produced in the manner described in any one. of the foregoing examples, to which solution a filling material such as talc or china clay or zinc white (for instance 100 to 200 per cent calculated on the weight of the precipitable cellulosic substance) or a dyestuff or a pigment, such as mica, or lampblack, may be added and without being dried,'if necessary in a state of tension, is pressed through a bath having the composition of one of the coagulating liquids mentioned in Patent 2,021,861. Thedressed or coated cloth is then washed and dried.

In the above description, reference is made repeatedly to the fact that the ethers of cellulose to be xanthated, in the present invention are in most cases alkali-soluble, that is to say, they can be dissolved in aqueous caustic alkali solutions. This statement is not intended to mean that the ethers will necessarily dissolve in caustic alkali solutions in water at .room temperature, 7

but they can be readily dissolved in the aqueous caustic alkali solution in the cold (e. g. at 0 C., or at between-10 C. and +5 C.) and the solutions then allowed to warm up to room temperature. V

The amount of the substituted radical, e. g. alkyl, aralkyl or the hydroxy-acid radical, is relatively low, in these ethers.

The following Table 1 is given showing the alkyl content of the alkyl ethers formed by the alkylation treatment in several of the above examples. In said table, column A gives the example number, column B gives'the amount and kind of alkylating agent (stated as percentage of the weight of the cellulose .used). Column C gives the alkyl content in the etherifiedcellulose, (after purification and alkylation, and before xanthation) produced in carrying out the respective example, this being the results of actual analysis (by the Zeisel test). Column D shows the number of Csl-hcos-molecular units of cellulose, per one alkyl group in that particular product, this figure being computed from the data in column C.

Table 1 A B 0 1) I 10% MGZSOA 0.07% on; 12. 7 111 20% MezSOi V 1.37% on; 0. 5 1v 10% 1211801 1.08% 0,11, 11. 3 IV 20% EigSOi 1.49% CzH; 10.3 v 11-12.5% EtCl 1.38% can, 11. 1 Ex. loIl,5S9,606 11- 1%, 1 1.78% 0,11, s, 01

11- .1 1.59; o b-20%%1o 2.34%; 02 v1 290% 111,504 1.84% 0,11, s. 28 v11 220% lasso, 1.44% can, 10. 57

Other tests on similarly made products- G 60% M81804 1 60% CH3 5. 35 H 20% M82304 1.37% CH3 (1. 5 J 60% Et1$04 4.31% C111; 3. 51 K 30% nusoi 2 00% c1115 '1. 7a

Itwill be understood that in the above table,

Me2SO4 is used to mean dimethyl sulphate" and that M2804 is used to mean diethyl sulphate, and EtCl means ethyl chloride.

It will be observed that the alkylation reactions as given in the examples never produce the introduction of anything like the theoretical amount of the alkyl groups.

In the above Table 1, alkyl ethers only are discussed, and not the benzyl ethers or the glycollic acid ethers. This "is for the reason that no thoroughly accurate methods are known for making a determination of the benzyl group in the benzyl ethers of cellulose, nor for making a determination of the hydroxy-acid residue (e. g. glycollic acid residue) in the cellulose ethers containing these. But by computation from the amounts of cellulose and of benzyl chloride or of chloracetic acid used, it will be observed that the degree of substitution of the respective groups will necessarily also be relatively low] And the properties of these ethers (notably insolubility in the commonly used organic solvents and the solubility in aqueous alkali solutions) also indicate that the degree of substitution is relatively low.

In further researches of this inventor it has been shown that ethers of cellulose which contain less of the substituent radicals than indicated in the above examples, and which do contain less of the substituent radicals than would be necessary to give solubility in aqueous caustic alkali solutions (even by refrigeration) are still suitable for xanthation to give useful xanthate solutions, for the preparation of shaped artificial structures.

As a guiding line with regard to the question whether or not the alkali cellulose should be allowed to mature before being brought together with the etherlfying agent, may, among others, serve the desired viscosity of the solution which is to be worked up into artificial structures in general and artificial threads in particular, and in connection therewith the viscosity of the particular cellulose to be employed. If it is desired to give the solution a definite viscosity, then the alkali cellulose produced from the kind of cellulose contemplated is subjected to a maturing process, if without maturingflthis kind of cellulose yields a higher viscosity. If, however without maturing it exhibits the desired visccs-' ity, then maturing is superfluous. Now, as the viscosities of the many different kinds of cellulose on the market (linters and wood-pulp) differ very much from one another, the question of maturing depends in most cases on the one hand on the viscosity desired of the initial soluinto the shape of the desired artificial structure,

tion intended for the manufacture of artificial structures, and on the other, hand onthe viscosity of the kind of cellulose being'worked. H

Without restricting thepresent invention to any lower or upper limits of tenacities or extensibility, it may be mentioned by way of example that it is possible-to produce according to the present process artificial threads which have a dry tenacity exceeding 2 grams and even reaching or exceeding 5 grams per denier, that have a good extensibility, say of about '7 to 1-0 and in some cases even to per cent and more.

In the specification and'filaims; wherever the an alkali-soluble alkyl, ether of cellulose, xancontext permits, the expression cellulose inlose and in lieu of ,the xanthates of cellulose ethers of glycollic acid, xanthates of cellulose ethers of homologuesof glycollic acid, for example a xanthate of cellulose ether of lactic acid or hydroxy-butyric acid may be employed in the present invention. V

The expression strong mineral acids denotes sulphuric acid of at least 35 per cent of H2804, preferably at least 45 percent of H2804, and as regards the other mineral acids, solutions of equivalent strength.

The expression strong sulphuricv acid or sulphuric acid containing at least about 35 per cent of sulphuric acid monohydrate denotes sulphuric acid having a content of 35 to 98 per cent of H2804.

The expression shaped artificial structures" used in the specification and claims includes: Artificial threads, particularly artificial silk; films; coatings andll'ayers of every kind; dressing on textiles, paper, leather and the like, sizing on yarns; book cloth; artificial leather; adhesives and cements; plates and shaped plastic compositionsin general; thickening agents or fixing agents for pigments in textile printing and the like.

The xanthates and'methods of making same, as herein described are claimed in a copending application 365,392 filed November 12 1940 (which is largely a continuation of Ser. No.

and acting upon the shaped solution with acoagulating agent. c h

3. A process of making a shaped artificial, structure," which comprises giving to a solution containing a xanthate of a cellulose ether selected from the group consisting of xanthate of thate of an alkali-soluble aralkyl etlier of cellulose, and-xanthate of an alkali-soluble hydrbxy- I acid ether of cellulose, the shape of an artificial 7 structure by extruding said solution through a shaped opening directly into a coagulating bath,

and continuously drawing the 'coagulated artificial structure away from said shaped opening.

4. A processof making an artificial structure which comprises bringing'a solution containing a xanthate of'a. cellulose ether selected from the group consisting of xanthate of an' alkali-soluble alkyl ether of cellulose, xanthate of analkali-soluble aralkyl ether of cellulose and 'xan--- thate ofan alkali-soluble hydroxyl-aci'd ether of cellulose, into the form of an artificial structure, and coagulating and plasticizing such product.

5; A process as in claim 4, in which the coagulating and'plasticizing actions are efiected in a bath containing mineral acid 'equivalent in strength to sulphuric acid of at least 35% H2804.

6. A process which comprises treating a solution containing a xanthate of a' cellulose'ether selected from the group consisting of xanthate of an alkyl ether oi. cellulose, xanthate of; an aralkyl ether of cellulose and'xanthate of a hydroxy-acid ether of cellulosefand which ether contains only one substituent radical joined ether-fashion to several CsH oos-molecular units of cellulose, and while said solution has the form of an artificial structure, with a coagulating 521,023 filed March '7, 1931), the present case being in major part a continuation of copending allowed application 521,017, alsofiled March 7, 1931. I

The alkyl ethers of cellulose described herein, and the mode of preparing same are -not claimed herein but are claimed in a copending application 314,359, filed January 17, 1940.

What is claimed is:

1. A .process of making a shaped artificial product from a solution which contains a dissolved xanthate of an alkali-soluble cellulose ether other than a hydroxy-alkyl cellulose ether,

agent and plasticizing the freshly coagulated shaped structure. y

7. A process as covered in claim 2, wherein the xanthate solution to bewo'rkedhp into an artificial structure is produced'by treating with carbon bisulphide an at least partially dissolved cellulose ether selected from the group consisting of alkyl'ether of cellulose, aralkyl ether of cellulose and hydroxy-acid ether of cellulose, which ether is at leastpartially solubleincaustic alkali solution and insoluble in water.

8. The hereindescribed process of producing artificial structures of high tensile strength and. of at least fairly good extensibility which comprises introducing a shaped stream'of a solution" of a xanthate of an alkali-soluble"cellulose ethei' a. selected from the group consisting of xanthate of an alkyl ether of cellulose, xanthate of an aralkyl ether of cellulose and xanthate of ahydroxy-acid ether of cellulose. into a coagulating bath and plasticizing the freshly coagulated artificial structure, all without subjecting the formed artificial structure to additional stretchI 9.A process of making anartificial structure which comprises bringing a so'lution of a xanthate of an alkali-soluble alkyl ether of cellulose into the shape of thedesiredartificial structure, and

V the so shaped material.

structure which comprises treating alkali cellu lose with an alkylating reagent in such;propor-' trons as to produce an alkyl ether ofcellulose containing at least about 3.54CaH1oQs-molecular units of celluloseperone alkyl group, xanthat ing the cellulose ether so produced, dissolving the xanthated ether to form a viscous solution, giving the said viscous solution the shape'of the least one alkyl ether of cellulose, such product desired artificial structure',jand acting U on the so shaped solution with afcoagulating agent.

12. A process. which comprises spinning into an acid setting bath having an acidity equivalent to that of sulphuric acid of not substantially below 45% concentration, an alkaline solution of a Xanthate of an alkyl ether of cellulose, which ether contains an alkyl radical in amount equivalent to not substantially" over 4.31% of ethyl.

13. A process comprising dissolving in'dilute aqueous caustic, alkali solution, ananthate of a hydrocarbon ether of cellulose, said ether containing "onlyone hydrocarbon ether group to a plurality of CbHmos-molecular units ofjcellulose,

extruding the solution into an acid, coagulating bath, and washing and dryingthecoagulated product.

aqueous'caustic alkali solution, a xanthate of an.

only one ethyl group to a pluralityof CsHrcOs-y,

. lution into an acid coagulating bath, and wash- 1 molecular units of cellulose, extruding the soing and drying the coagulated product.

15. A process of making a regenerated artificial structure which comprises treatingalkali' cellu; lose with a reagent containingthe. acid radical of a halogenated fatty acid, xanthating the celbeing-made by contacting a shaped solution con-J taining a" xanthate of an alkali-solubl alkyl ether oi'cellulose, with a coagulating bath.-

20; Asa new product, an artificial structure which is composed essentially of an alkyl ether of cellulose, regenerated from a xanthate' of an alkali-soluble alkyl ether of cellulose.

21. A structure cognprising a "hydrocarbon ether of cellulose which contains only one hy-- drocarbon ether group to a plurality of CeHroOaj molecular units of cellulose, said cellulose ether being regenerated from a solution or a xanthate thereof. V s

22. A textile product having a dressin wmmcontains a cellulose ether selected from the'group consisting of" all-ryl ethers of cellulose, aralkyl ethers of cellulose and hydroxy-acid others of cellulose, which textile product isproduced by applying to a teic'tile material a dressing contain- 1 ing an aqueous alkalin solution of a'xanthate MIA process coinprisingdissolving in dilute-''" of an alkali-soluble ether of cellulose selected iromsaid group, and coagulating said solution I Y while carried by said textile material. ethyl ether of cellulose, said ether containing 23. An artificial thread or'iilament containing a cellulose ether selected from the group consisting of alkyl ether'oi cellulose, aralkyl'ether of cellulose and hydroxy-acid ether of cellulose such product having a dry tenacity of over 2 grams per denier," and' an extensibility of over 10%, which-product is produced by shaping a lulose ether so produced, dissolving the xanthated ether to .form a viscous solution, giving the said viscous solution the shape of, the desired artificial structure, and acting upon the' i shaped solution with a setting bath containing not substantially below of HzSOr, s s

16. As a new product, a shaped artificial strue tur containing a cellulose ether selected' fro the group consisting of alkyl'eth'er otrcellulose, aralkyl ether of cellulose and hydroxy-acid'ether of cellulose, and which product has 'aitenacityg; in the dry state, equivalent to over. Zfgran'is; per; denier and which product'l has fan? extensibility of at least 10%,v which'produc't isproducedb'y shaping a solution of a xanthate of an alkalisoluble cellulose ether selected from itheygro'upsolution of 'a ranthate of a cellulose ether selected from the. group consisting of xanthate of an' of an and anthate of an .alkali-soluble hydroxy acid ethe of cellulose into the appropriate shape, and coagulating the so shaped material.

2,4. As a new; product, an artificial thread which; consists essentially of at least one cellulose alkali 'solub,le 'alkyl ether of cellulose, xanthate etherselectedgfrom the groupconsisting'of alkyl' ether ,ofcellulose, aralkyl ether of cellulose and ihydroxy acid ether of cellulose, which thread has T fa dry tenacityzexceeding 2 grams Jan extensibilitycver 10%. V

tainin'g a cellulose'ether selected from the group 1- consisting ,of alkyl ether of cellulose, aralkyl I l ether of celluloseand hydroxy-acid ether 0! consisting of-xanthat'etof an alkyl etheryof eel-.4

lulose, xanthate of an aralkyl ether-of cellulose and xanthate of a hydroxy-ac'id ether of cellucellulose,} which thread has a dry. tenacity ex-' ceeding ,2. gra ms 'per: denier, and a wet tenacity lose, into theappropriate shape,.and coagulating I 17. As new products, ashapedartificial'struc ture containing a' cellulose ether selected from the group consisting of alkyl ether of cellulose,

aralkyl ether of cellulose and hydroiry-acid ether. 2

of celluloseand which products have a. dry) tenacity equal to that of a thread having a dry tenacity of not less than 2 grams'per. denier.

1,8. As anew product, a shaped artificial structure, which has a dry tenacity equivalent to more than 2 grams per denier and which contains an ether of cellulose other than a hydroxy alkyl, ethensuch product being made by contacting ashaped solution containing a xanthate of an alkali-soluble cellulose ether other than a hydroxy-allryl ether, with a coagulating bath.

exceeding 1 grain per denier,land an extensibility I exceeding 10%; tj .26. A 'threadfcornprising a; cellulose-ether of Y up to one hy droca rb0n ether fgroup' to 3.54

csHioosemol ecular units oi cellulose, said cellulose -ether/ beingi regenerated from a solution made bycontacting a shaped solution of a xanthate. of an aralkyl ether of'cellulose with a colkali-soluble aralkyl ether of cellulose per denier, and 25.1 As anew,v product, an. artificial, thread conjproduct shaped artificial thread .whichpasa dry tenacityequivalent to more than I 2 grams per denier and; which contains at least one aralkyl etherjof cellulose, such product being 

